Videoconferencing systems are typically designed to operate over terrestrial networks using unicast platforms based on H323 and Session Initiation Protocol (SIP) protocols. Each videoconference terminal sends and receives video signals to the other participating terminals. The videoconference is established by having unicast bi-directional connections between the video terminals. So, a videoconference having three sites A, B, C would require three unicast connections: A-B, A-C, B-C; and, a videoconference between four sites A, B, C, D would require six unicast connections: A-B, A-C, A-D, B-C, B-D, C-D. Each connection requires a channel with sufficient bandwidth to send and receive the video signals, so that the total bandwidth required is cumulative. If each of the three unicast connections in a 3-way videoconference required a 2 Mbit bandwidth, the total videoconferencing system would require 6 Mbit of bandwidth (2 Mbit×3 channels). However, this type of system is costly, inefficient and prone to failure.